Bug 35943: Fix group/subgroup filtering of saved reports

Bug 35943: Fix group/subgroup filtering of saved reports

Use code instead of name for filtering and escape regexp special
characters.

This patch also disables datatables' smart filtering as it is not
recommended to use with regexp filtering

https://datatables.net/reference/api/search()

Test plan:
1. Create a report in a group named "Foo + Bar" and in a subgroup named
   "Baz + Quux"
2. Create other reports in group "Foo + Bar" but in other subgroups, as
   well as in other groups. This is useful to see the effect of
   filtering
3. Go to the saved reports page and verify that navigating between tabs
   have the desired result. Same for the subgroup select

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>